1. Field of the Invention
This invention relates to a method of buffing a workpiece of nonferrous metals such as aluminum and brass to a scratch-free mirror finish.
2. Prior Art
For articles of nonferrous metals such as aluminum and brass, for example, watch cases, eyeglass frames, table ware, aluminum pans, aluminum door knobs, and automotive aluminum wheel bases, their surface gloss is now of greater importance. It is strongly desired to provide a scratch-free smooth surface in order to meet the decorative requirement as well as the functional requirement.
One typical prior art mirror finish polishing method is a buffing method using a fat bound buffing compound. This method, however, is not fully satisfactory in meeting the demand of a scratch-free smooth surface since abrasive grains introduce mars in the buffed surface.
An electrolytic composite polishing method was proposed in the art to overcome the above-mentioned problem. In polishing a workpiece having a two or three-dimensional curved surface, it was difficult to keep the electrolytic current, voltage and other parameters uniform. The electrolytic composite polishing method was thus limited to the polishing of planar sections. The method also had the problems of complex equipment and an increased polishing cost.